Considerable attention has been directed toward the morphologic changes which occur in the biliary system following surgical removal of the gallbladder. There are, however, practically no data available regarding the effect of cholecystectomy on the functional efficiency of the liver. At first it seems improbable that mere removal of the gallbladder should exert any deleterious effect on hepatic function. However, every surgeon of experience in this field has encountered instances of serious postoperative morbidity and even death following simple cholecystectomy in patients who were apparently in good condition before operation. A variety of factors are involved in the production of many of these postoperative calamities, e. g., anesthesia, undetected hepatic damage, renal complications, operative trauma and shock. In certain cases, however, the most careful preoperative study fails to reveal any significant hepatic or renal functional impairment; cholecystectomy is performed with no undue trauma; anesthesia, general, spinal or local, is apparently